How Does Reverse Osmosis Work?
How Does Reverse Osmosis Work?
Reverse osmosis is the gold standard for drinking water purification. Here's how it works and why it's so effective.
The Osmosis Principle
In natural osmosis, water moves through a semi-permeable membrane from a less concentrated solution to a more concentrated one. Reverse osmosis does the opposite — it applies pressure to force water through the membrane from the concentrated (contaminated) side to the clean side, leaving contaminants behind.
The RO Filtration Stages
A typical under-sink RO system has 4–5 stages:
- Stage 1 — Sediment pre-filter: Removes sand, silt, and particles that could damage the membrane.
- Stage 2 — Carbon pre-filter: Removes chlorine, chloramine, and organic compounds that could damage the membrane.
- Stage 3 — RO membrane: The core of the system. Removes up to 99% of dissolved contaminants — TDS, nitrates, sodium, heavy metals, fluoride, and more.
- Stage 4 — Storage tank: Purified water is stored in a pressurized tank under the sink.
- Stage 5 — Carbon post-filter (polishing): Final taste and odor improvement before the water reaches your faucet.
What RO Removes
A properly functioning RO system removes: dissolved solids (TDS), nitrates, sodium, fluoride, arsenic, lead, chromium, radium, barium, copper, and most other dissolved contaminants. It also removes some bacteria and viruses, though it's not a substitute for disinfection.
RO and Water Softeners
In Citrus County's hard water, an RO system works best when installed after a water softener. The softener protects the RO membrane from calcium and magnesium scaling, extending membrane life significantly. Aqua Logic installs both systems and can design the right combination for your home.
Have Questions About Your Water?
Schedule a free water test — we'll identify exactly what's in your water and recommend the right solution.